Back in the olden days when we made our own multilayer boards we used a
double pin system. The pins were of different diameters and slightly offset
to help assure proper layering and alignment polarity.The pins were press
fitted into the lower platten and a slip fit in the top platten. I don't
ever remember us having an alignment problem with this system.
Good luck with what ever system you decide upon.
Ron Dieselberg

-----Original Message-----
From: Nancy M. H. Holloway [mailto:[log in to unmask]]
Sent: Tuesday, January 04, 2000 10:41
To: [log in to unmask]
Subject: [TN] alignment flex circuits


Dear TechNet,

   What kind of alignment systems are available for laying up multilayer
flex circuits just before consolidation?  I have been "hand" aligning my
patterns and sometimes use a pinning bar, but with layer count increasing,
this is becoming more difficult.  I get better results with hand aligning,
versus using a pinning bar.  However, when I use the pinning bar, only one
side of the films are pinned, perhaps I need to have at least two or more
sides pinned to ensure alignment.  Any thoughts on this anyone?

                                Thanks,
                                Nancy

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